LC78620E Datasheet, PDF (14/34 Pages) Sanyo Semicon Device – Compact Disc Player DSP

LC78620E
• CLV three value output
MSB
LSB
10110100
10110101
Command
CLV THREE VALUE OUTPUT
CLV TWO VALUE OUTPUT
(the scheme used by previous products)
The CLV three-value output command allows the CLV to be controlled by a single pin.
RES = low
q
• Internal brake modes
MSB
LSB
11000101
11000100
10100011
11001011
11001010
11001101
11001100
Command
INTERNAL BRAKE ON
INTERNAL BRAKE OFF
INTERNAL BRAKE CONT
INTERNAL BRAKE CONTINUOUS MODE
RESET CONTINUOUS MODE
TON MODE DURING INTERNAL BRAKING
RESET TON MODE
RES = low
q
q
q
— Issuing the internal brake-on (C5H) command sets the LC78620E to internal brake mode. In this mode, the disk
deceleration state can be monitored from the WRQ pin when a brake command (06H) is executed.
— In this mode the disk deceleration state is determined by counting the EFM signal density in a single frame, and
when the EFM signal count falls under four, the CLV^– pin is dropped to low. At the same time the WRQ
signal, which functions as a brake completion monitor, goes high. When the microprocessor detects a high
level on the WRQ signal, it should issue a STOP command to fully stop the disk. In internal brake continuous
mode, the CLV^– pin high-level output braking operation continues even after the WRQ brake completion
monitor goes high.
Note that if errors occur in deceleration state determination due to noise in the EFM signal, the problem can be
rectified by changing the EFM signal count from four to eight with the internal brake control command (A3H).
— In internal braking TON mode, the TOFF pin is held low during internal brake operations. We recommend
using this feature, since it is effective at preventing incorrect detection at the disk mirror surface.
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